This invention relates to a tool and method for seaming interlocking metal panels, and more specifically to a tool and method useable in the fabrication of air circulating ducts and other structures for forcing a bent metal flange of a first panel within a channel formed by a second panel. Typically such joints are used to seam together ducts wherein the panels to be attached are adjacent duct sides which are formed by bending flat sheet stock. Assembly of such ducts is accomplished according to the prior art by striking the surface of the first panel with a hammer near the flange thereby driving the flange into the channel of the second panel. The seam is secured when the upstanding flange of the second panel is bent over the first panel thus forming an interlocking joint. Optimally, the hammer impact should occur along the corner of the first panel formed by the flange, thus inserting the flange securely within the channel. Use of conventional hammers for driving the panels together, however, leads to construction flaws since hammer blows cannot be precisely aimed and the hammer striking surface is not tailored to this specific application. If the hammer strikes the panel surface any appreciable distance from the flange, denting of the typically thin gauge sheet metal is likely. On the other hand, if the hammer strikes the joint itself damage to the upstanding flange is likely. Moreover, even a precisely aimed hammer blow can cause panel damage. For these reasons, assembly using conventional hammers to seam the panels is time consuming and often results in poor appearance of the finished product.
In accordance with this invention, an improved duct seaming tool and method is disclosed which overcomes the shortcomings of the prior art as described above. The improved seaming tool accurately positions an anvil near the panel flange. By striking the tool with a conventional hammer, the impact force is directed to the duct joint thereby preventing panel damage since other panel areas are not impacted. Additionally, since the tool directs the hammer impact force accurately, less effort is necessary and fewer blows are required to join the panels and a more secure joint is formed. The tool according to this invention further allows rapid fabrication even by inexperienced personnel.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates upon a reading of the description of the described preferred embodiments of this invention taken in conjunction with accompanying drawings.